贷款计算机实验报告.doc

高级Java编程技术课程实验报告院（系）名称：计算机学院 专业班级：学号： 姓名：实验题目：实验3自定义类1实验日期：2011/10/11 实验（上机）学时： 2一、实验内容、要求1. 实验内容：贷款计算机2. 要求： 编写贷款计算程序，根据给定的贷款金额、年利率及贷款期限，计算月支付金额及总支付金额。这个程序流程可以表示为下面的三个任务：（1） 获得三个输入值：loanAmount（贷款金额），interestRate（年利率），loanPeriod（贷款期限）。（2） 计算月支付金额及总支付金额。（3） 输出结果。.本次实现的主要区别是新加入类的使用。不像以前那样把所有的任务都放在主类里，现在定义Loan和LoanCalculator两个类。LoanCalculator类的一个实例在程序中起一个管理者的作用，管理着这个程序的其他类的对象。Loan类是一个提供服务（例如：计算贷款，货币转换）的类。二、所采用的数据结构如：线性表，二叉树，树，图等。无数据结构。三、实验的主要模块（或函数）及其功能函数分块及各块主要功能的文字描述（1）LoanCalculator类。包含一个对象或一个变量的声明，一个构造方法一生成该对象。定义一个Loan类。获得输入贷款金额、年利率、贷款期限值，实现接受输入值的功能，且将结果显示出来的功能。还有输出月利率、总支付次数、总支付金额的结果的功能。public class LoanCalculator private Loan loan;public static void main(String args) LoanCalculator calculator = new LoanCalculator();calculator.start();public LoanCalculator() public void start() describeProgram();getInput();displayOutput();private void describeProgram() System.out.println(This program computes monthly and total);System.out.println(payments for a given loan amount,annual );System.out.println(interest rete,and loan period (# of years).);System.out.println(n);private void displayOutput() System.out.println(Loan Amount: $ + loan.getAmount();System.out.println(Annual Interest Rate: + loan.getRate() + %);System.out.println(Loan Period(years): + loan.getPeriod();System.out.println(Monthly payment is $ + loan.getMonthlyPayment();System.out.println(Total patment is $ + loan.getTotalPayment();private void getInput() double loanAmount, annualInterestRate;int loanPeriod;String inputStr;inputStr = JOptionPane.showInputDialog(null,Loan Amount(Dollars+Cents):);loanAmount = Double.parseDouble(inputStr);inputStr = JOptionPane.showInputDialog(null,Annual Interest Rate(e.g.9.5):);annualInterestRate = Double.parseDouble(inputStr);inputStr = JOptionPane.showInputDialog(null,Loan Period - # of years:);loanPeriod = Integer.parseInt(inputStr);loan = new Loan(loanAmount, annualInterestRate, loanPeriod);（2）Loan类。实现可以计算月利率、总支付次数、月支付金额和总支付金额。class Loan private final int MONTHS_IN_YEAR = 12;private double loanAmount; / 贷款金额private double monthlyInterestRate; / 月利率private int numberOfPayments; / 支付次数public Loan(double amount, double rate, int period) setAmount(amount);setRate(rate);setPeriod(period);public double getAmount() return loanAmount;public int getPeriod() return numberOfPayments / MONTHS_IN_YEAR;public double getRate() return monthlyInterestRate * 100.0 * MONTHS_IN_YEAR;public double getMonthlyPayment() double monthlyPayment;monthlyPayment = (loanAmount * monthlyInterestRate)/ (1 - Math.pow(1 / (1 + monthlyInterestRate), numberOfPayments);return monthlyPayment;public double getTotalPayment() double totalPayment;totalPayment = getMonthlyPayment() * numberOfPayments;return totalPayment;public void setAmount(double amount) loanAmount = amount;public void setRate(double annualRate) monthlyInterestRate = annualRate / 100.0 / MONTHS_IN_YEAR;public void setPeriod(int periodInYears) numberOfPayments = periodInYears * MONTHS_IN_YEAR;四、主要模块（或函数）的算法思想和程序框图具体算法实现文字描述或框图：主类：class LoanCalculatorLoan loan;main( )start( )getInput()输入贷款金额 loanAmount(),输入年利率,annualInterestRat(),输入贷款期限 loanPeriod()调用Loan的构造函数进行赋值。describeProgram()描述程序的功能displayOutput()输出计算结果调用Loan类getAmount()getRate()getPeriod()getMonthlyPayment() 计算月支付 金额getTotalPayment() 计算总支付金额月支付金额=(L*R)/1-1/(